Process of producing fine fiber artificial silk



30 ing'i'ron hydrate "whic Patented Mar. 26, 1929.

UNITED STATES ZTPA'TENT ol-" cs ALBERT WAGNER, or enoss-zscnacnwrrz, arm mmsnnmpeaanny, Assnmon tro THE mam FR. xur'man, or rmm, saxomr, Grimm.

raocnss or rnonucme rnm rnmn atrium-relax. SILK.

no Drawing. Application filed 1...]. as, 1021, Seriallo. 178,507, and in Germany June 11, im.

The production of fine. fiber artificial silk from a solution of ammoniated copper oxidecellulose according to the well-known stretch spinning process has hitherto been effected by treating the spun silk, for whlch'water was used as stretching medium, after passing out from the spinning funnel- .in a 12% water solution of sulphuric acid, as a result of which cellulose hydrate is produced. The

thus hardened silk has a comparatively b lity when dry.

small degree of elasticity and plasticity. The cellulose fiber containing copper 1n wet condition is more plastic than that con-- taining no copper or but very little. It has 15 therefore already been suggested to carry out the hardening process so that even when using SUlPhllllC'iLCld as a precipitating medium, the fiber will still retain its copper.- I It is, however, technically diflicult to carry out this method so that the-thread will re-v tain the copper and only lose the ammonia which acts as a solvent and produces stickiness.

By employing a well known process with iron sulphate, it is possible to produce a cellulose fiber contaimng co per whose individual threads will not stick .together. The

employment of iron sulphate because of the separation'of ammonia reduces selfoxidizii when freed from copper is-objectionable. 1

I have found that a water solution of aluminum sul hate can be adv'anta eously used as a har enin medium. The fi r derived from such a bath contains. in addition to copper, residues of sulphuric acid and aluminum. About half of the whole fiber-- same in sulphuric acid,

consists of cellulose. The eflect of this method is that the individual threads easily separate from one another and that a green 40 co per cellulose fiber is produced which w en wet is plastic to the hi hest degree,

so thata silk is produced whidii' is very exspansible. vThe plasticity of the wet'fiber containin copper is so high that even when .46

.acids such as sulp uric acid or the like may he i be added to the aluminum sulphate in order to dissolve the aluminum hydrate not lab sorbed bythe fiber.

The bath, either cold or warm, is advan 'tageously made u of a 12% water solution of aluminum sulp ate.

What I claim is A 'processof producing finefiber artificial silk, consisting mfirst forming strands from a solution of ammoniated copper oxide cellu- U lose according to the-stretch spinning method, then treating said strands in abath containing a solution of aluminum sulphate, then winding said strands on spools or the 1 like, then washing them, then treating the 10 then in washing andfinallydryin ga In testimony wiiereof I afiix my si aturej. r K ALBER'rwAe B. 

